World number two Victoria Azarenka reached her second successive US Open final on Friday with a 6-4, 6-2 win over Italian veteran Flavia Pennetta in a match featuring 13 breaks of serve.
Azarenka goes on to face either world number one and defending champion Serena Williams or Chinese fifth seed Li Na in Sunday's title match.
It was Australian Open champion Azarenka's third successive semi-final appearance in New York, but she will need to step it up in the final after committing six double faults and 25 unforced errors.
"I am so excited to be back in the final and get the chance to fight for the trophy," said Azarenka.
"It was a great match today. There were lots of emotions. It was tricky because I struggled to find any rhythm and Flavia is such a great fighter. I couldn't get a ball in play."
She added: "In the final, I will be facing a great player, whoever it is. I will have to give it all I have got, all my heart, all my body and all my mind."
In a tense, error-hit first set there were seven breaks of serve in 10 games with Azarenka, who had spent two hours more on court getting to the semi-finals than her opponent, struggling to impose her authority.
Azarenka, last year's runner-up to Williams in New York, eventually closed out the opener on a sixth point after a 10-minute game.
Pennetta, bidding to be the first Italian woman to make the US Open final after missing the 2012 tournament due to a wrist injury, had saved two of them with a couple of scintillating groundstrokes, one off either wing.
It wasn't pretty for Azarenka, who served up five doubles faults in the set and hit 18 unforced errors.
The second set also got off to a rocky start with three successive breaks of serve before the 23-year-old world nunber two managed to hold for 3-1 and break the flagging Italian again for a 4-1 advantage.
Pennetta called for water at the changeover but would have been better off pleading for mercy after being broken for the seventh time in eight service games.
The 31-year-old Italian, now ranked 83 but who had defeated three seeded players to reach the last four, clung on and broke back before she surrendered the advantage yet again, dropping serve for the eighth time.
It was her last chance. Azarenka went to three match points in the eighth game and claimed victory after 94 minutes with a wrong-footing forehand.